A highly sensitive spectrophotometric determination of platinum(IV) using leuco xylene cyanol FF

Abstract

A new, simple, highly sensitive and rapid spectrophotometric method has been described for the determination of platinum(IV). The method is based on the oxidation of leuco xylene cyanol FF (LXCFF) to its blue form of xylene cyanol FF by platinum(IV) in sulfuric acid medium (pH 1.0-2.5), the formed dye shows an absorption maximum at 620 nm in acetate buffer medium (pH 3.0-4.5). The method obeys Beer's law over a concentration range of 0.3 to 2.6 micro g mL(-1) platinum, having molar absorptivity and Sandell's sensitivity of 5.1x10(4) L mol(-)(1) cm(-1) and 0.0038 micro g cm(-2), respectively. The optimum reaction conditions and other analytical parameters have been evaluated. The developed method has been successfully applied to the determination of platinum in pharmaceutical preparations, soil, natural water, plant material, platinum-containing catalyst, and synthetic alloy samples.

Spectrophotometric Determination of Traces of Platinum with 5-Chloro-2-hydroxythiobenzhydrazide after Extraction into Molten Naphthalene

“…6 The use of thiohydrazides such as o-hydroxythiobenzhydrazide, 7 thiobenzhydrazide, 8 α-naphthalenethiocarboxhydrazide, 2-pyrrolthiocarboxhydrazide, furanthiocarboxhydrazide, thiophenethiocarboxhydrazide, 9 dibenzylidenethiocarbohydrazide, 10 and 2-furancarbothioic acid hydrazide 11 in the spectrophotometric determination of rhenium and platinum group metals has been described in a number of papers. Other reagents such as dithizone, 12 anisaldehyde-4-phenyl-3-thiosemicarbazone, 13 dithizone-polyurathane, 14 4-phenylthiosemicarbazide, 15 3-(2′-thiazolylazo)-2,6-diaminopyridine, 16 N-(m-methylphenyl)-N′-(sodium p-aminobenzenesulfonate)-thiourea, 17 piperonal thiosemicarbazone, 18 and leuco xylene cyanol FF, 19 have been reported for spectrophotometric determination of platinum after liquid-liquid extraction. The reagents phenanthrenequinone monoximes 20,21 and 1-(2-pyridylazo)-2-naphthol 22 have been used for spectrophotometric determination of platinum after solid-liquid extraction.…”

“…These methods suffer from some drawbacks, such as a longer waiting period for color development, 7,9 a need for multiple extractions for quantitative recovery of the metal, 8 presence of stannous chloride, 12,14 narrow pH range, 10,13,19 high molarity of aqueous phase, 14,16 low absorptivity, 15 low sensitivity 13,20 and low stability of the reagents, [7][8][9] as shown in Table 1. None of these methods allow the separation and separate determination of platinum and rhenium.…”